1. Field of the Invention
The invention is a magnetic pick-up tool with at least a second, removable magnet seated in a handle receptacle that can be placed on the magnetic pick-up head for increasing the attractive magnetic field strength of the tool.
2. Description of the Prior Art
Magnetic pick-up tools are well known and widely used for retrieving dropped items such as nuts, bolts, screws, fasteners, tools and the like composed of magnetically susceptible materials from crannies inaccessible to hands and fingers. Such tools typically included a pick-up head presenting a pole face of a cylindrical bar magnet fastened by a holder at the end of an extensible (telescoping), bendable or flexible probe. (See U.S. Pat. No. 2,428,862 C. R. Boyd, U.S. Pat. No. 5,945,901 Coleman Jr. et al, & U.S. Pat. No. 6,677,845 Fader et al.) Typical holders are composed of a non-magnetically susceptible material, although, holders composed of magnetically susceptible materials have been found to increase the attractive or adhering magnetic force or field strength of the pick-up head pole face. (See U.S. Pat. No. 6,677,845 Fader et al.)
Some embodiments of magnetic pick-up tools feature translatable sleeves of magnetically susceptible materials disposed around the pick-up head for shielding or redirecting magnetic flux emanating between the poles of the magnet thus mitigating or reducing radial attractive forces along the length of the pick-up head. Such shielding enhances the utility of the tool in tight surroundings composed of magnetically susceptible structures. (See Coleman Jr. et al & Fader et al supra) In particular, without such shielding, the attractive magnetic forces of the pick-up head at the end of the probe cause it to adhere to the surrounding structures frustrating efforts to move it to pick up the dropped item.
Present rare earth, metal-based, permanent magnets such as Ne—Fe—B magnets provide high magnetic field strengths emanating from relatively small volumes. For example, a rare earth, metal-based, permanent magnet pellet 10 mm in diameter, and 5 mm in length in a ‘larger’ magnetic pick-up tool manufactured by CE Tools in Taiwan (Model No S5012-A) purportedly provides sufficient attractive force to retrieve dropped items weighing 3.5 lbs. (1.59 Kg.) A Gooseneck LED Light with Magnetic Pickup with a slightly larger, ‘shielded’ pick-up head marketed over the Internet at www.autosportcatalog.com by Auto Sport located in Charlottesville Va. boasts an attractive force capable of retrieving 5 lbs. (2.7 Kg.) articles. These larger diameter pick-up heads are limited both by size and magnetic field strength from probing into smaller crannies that all to frequently capture dropped items. While shielding (see Fader et al supra) can abate deleterious effects of magnetic field strength, it also increases pick-up head diameter.
Magnetic pick-up tools with smaller a rare earth, metal-based permanent magnet pellets having diameters less than 10 mm and 5 mm in length and lower magnetic field strengths, conversely are limited by those factors from retrieving larger (heavier) dropped items captured by lager crannies. In particular, the ratio of the surface areas of the pick-up magnet pole faces and available magnetic field do not provide sufficient adhering or attractive force to retrieve heavier items weighing in 3-5 lbs. (1.3-2.7 Kg.) range.